Zero-emission reuse treatment method for electroplating cyanide-containing wastewater

Abstract

The invention discloses a zero-emission reuse treatment method for electroplating cyanide-containing wastewater and relates to a wastewater treatment technology. The wastewater is sent to a raw water regulation pool and then passes through a photocatalytic oxidation reactor and a membrane coagulation gas flotation reactor successively; back flushing outflow water of the membrane coagulation gas flotation reactor flows back to the raw water regulation pool; the outflow water of the membrane coagulation gas flotation reactor is sent to a continuous membrane filtration system for filtering, concentrated liquor of the continuous membrane filtration system and back-flushed water flow back to the raw water regulation pool; outflow water of the continuous membrane filtration system passes through a reverse osmosis system, an anion exchange column, an electro-adsorption reactor and a cation exchange column successively, and outflow water of the cation exchange column is recyclable purified water; eluted concentrated water of the electro-adsorption reactor and concentrated water of the reverse osmosis system are sent to a reverse osmosis concentrated water collecting pool, and outflow water enters a membrane contact reactor for cyanogen recovery; outflow water of the membrane contact reactor is sent to the electro-adsorption reactor, and metal electroplating liquid is obtained through evaporation, crystallization and concentration of eluted concentrated water; and outflow water of the electro-adsorption reactor is sent to the cation exchange column, and the outflow water is recyclable purified water.

Description

technical field [0001] The invention relates to a wastewater treatment technology, in particular to a method for treating cyanide-containing wastewater from electroplating to achieve zero discharge and reuse. Background technique [0002] Cyanide-containing wastewater is mainly produced in rare metal smelting and electroplating production. Among the many types of plating, cyanide plating is one of the commonly used plating types, mainly used for zinc plating, lead plating, cadmium plating, copper plating, silver plating, and gold plating. In the cyanide-containing wastewater, in addition to highly toxic free cyanide, there are complex ions such as copper cyanide, cadmium cyanide, silver cyanide, and zinc cyanide. The concentration of CN- in the wastewater is high, and it also contains a large amount of heavy metals, thiocyanate and other compounds, which seriously pollutes the external water environment. Cyanide is a highly toxic substance. CN- will combine with ferric cyt...

AI Technical Summary

Problems solved by technology

The concentration of CN- in wastewater is relatively high, and it also contains a large amount of compounds such as heavy metals and thiocyanate, which seriously pollutes the external water environment.